Alternate make-break pushbutton switch assembly with detent means, indicator and indicator slide switch structure

ABSTRACT

A push button switch having a plunger that is movable axially through a housing to selectively engage and disengage contacts by the position of the plunger; a push button that operates upon the end of the plunger to axially shift it; a return spring for the plunger and a separate return spring for the push button, such that the push button and plunger are both normally biased to their return or outward position; detent means hold the plunger in the depressed position, while the push button returns outward; various abutment arrangements are shown for connecting the springs and push buttons and plunger; in a modified embodiment, the push button, instead of being axially operative, is a pivoting key with a lever that is pressed axially against the end of the plunger by pivoting of the key.

United States Patent 1 Schadow 1 Feb. 18, 1975 [54] ALTERNATE MAKE-BREAKPUSHBUTTON 3,598,948 8/1971 Bowen et a1. 200/153 I X SWITCH ASSEMBLY I HDETENT 3,639,714 2/1972 Fujimoto et a1 200/153 1 3,776,049 12/1973 Emery200/153 .1 X

MEANS, INDICATOR AND INDICATOR SLIDE SWITCH STRUCTURE lnventor: RudolfSchadow, Konigsbacher Zeile 23, 1 Berlin 28, Germany Filed: July 27,1973 Appl. No.: 383,332

[30] Foreign Application Priority Data Sept. 6, 1972 Germany 2243639References Cited UNITED STATES PATENTS 11/1947 Schellman 200/313 X3/1953 Larsen et a1 200/166 BA X 6/1971 Schadow ZOO/159 R S 3 L l 7Primary Examiner lames R. Scott Attorney, Agent, or FirmOstr0lenk,Faber, Gerb & Soffen 5 7] ABSTRACT A push button switch having a plungerthat is movable axially through a housing to selectively engage anddisengage contacts by the position of the plunger; a push button thatoperates upon the end of the plunger to axially shift it; a returnspring for the plunger and a separate return spring for the push button,such that the push button and plunger are both normally biased to theirreturn or outward position; detent means hold the plunger in thedepressed position, while the push button returns outward; variousabutment arrangements are shown for connecting the springs and pushbuttons and plunger; in a modified embodiment, the push button, insteadof being axially operative, is a pivoting key with a lever that ispressed axially against the end of the plunger by pivoting of the key.

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I V/ I PATENTEDFEB! a :2:

sum 3 OF 5 ALTERNATE MAKE-BREAK PUSHBUTTON SWITCH ASSEMBLY WITH DETENTMEANS, INDICATOR AND INDICATOR SLIDE SWITCH STRUCTURE BACKGROUND OFINVENTION 1. Field to which invention relates The present inventionrelates to a switch component, more particularly for making up rows orblocks of push button switches.

2. The prior art Mechanical push button switch units, more particularlythose with mutual release of the switches, as used in the wavelengthswitch arrangements in radio and TV technology or in electronicsgenerally are subject in the main to two substantial disadvantages: Themechanical switching noise, which in some circumstances may also giverise to electrical interference, or its mechanical shock action damagessensitive components such as incandescent lamps, and there is thedefective alignment of the push buttons arranged close alongside oneanother in a greater or smaller number.

Many constructions have been proposed for damping the mechanicalswitching noises; the simplest construction involving the use ofrubber-like abutments for the push button plungers flicked or snappedback by spring force, is usually unsuitable owing to the largetolerances resulting as regards the terminal position of the pushbuttons, for in the case of varying spring forces in accordance with thenumber of switching operations carried out on a specific push button asoft abutment is compressed to a greater or lesser extent. If, on theother hand, the spring forces are made equal, the damping action isreduced.

The mechanical switching noise increases with an increase in the mass ofthe switch plungers; the push button which in most cases is connectedwith it in a fixed manner, however, has a larger weight than the switchplunger. The mechanical separation of the two is therefore obvious andhas already been proposed, although it has been adopted more for otherreasons. The mechanical construction for dealing with the problem was,however, too expensive because it was necessary to arrange a push buttonmechanism in front of the whole switching unit so as to form a secondunit and at the same time this front unit had to fulfill the task ofproviding optical indication of the switching on of a switch, for bymeans of pressure on a push button although the respective switch slideis brought into its detent-held position, the push button itself springsback into its starting position.

SUMMARY OF INVENTION In accordance with one aspect the present inventionconcerns an improvement in conventional groups of push button units madeup of push button switch components and involves an addition to thecomponent housing which is supplemented by a cover plate to form a tubeand usually having a U-shape, in the form of a front unit which guidesthe push button in a suitable manner. The push button and the switchslide possess independent return springs and abutments, and in thisrespect it is possible to take steps so that the push button head can heremoved from the front against a certain resistance and can be placed inposition again, something which is also possible in some cases in thecase of the switch slide after removal of a locking means.

In accordance with a further aspect the present invention consists in aswitch component. more particularly for making up rows or blocks of pushbutton switches, characterised in that a switch plunger and a pushbutton are carried in the same component housing but independently fromeach other, in that the detent means fixing the switch position act onthe switch plunger, which has a return spring and can only be displacedpreferentially in the thrust direction by means of the push buttonprovided with a second return spring.

In accordance with a further development of the principle of theinvention the push button or the component has at the front a mechanicalswitch position indicating means, which is operated by the switch slide.

In accordance with another possibility an interchangeable or replaceablefitting with an indicating lamp is incorporated in the push button andin this case in the front unit of the component housing contact leadmeans are provided for this lamp fitting and possibly in addition aseparate lamp switch'is provided which is operated by the switch slide.

In accordance with a further development of the principle of theinvention in the front unit of the housing it is also possible toprovide for the journalling of,

a push button in the form of a see-saw or piano key. A particularlysimple indicating means for the switch position using a coloured slide,which moves under a win dow in the piano key, also forms part of thesubject matter of the application. In this case a single strip springcan bring about both indication and also the return of the key orbutton.

In accordance with a further proposal in accordance with the inventionfor the mechanical damping of the return impact of the switch slidesimultaneously use is made of a push button return spring which isweaker than the switch return spring, with the possible interpo-- sitionof a rubber disc, which furthermore or alone serves as a damping buffer.In some circumstances it may be more practical to arrange for the pushbutton return spring to rest against the housing independently of theswitch slide.

The front unit of the component housing is preferably made in one piecein order to reduce the number of parts to be used during fitting.

Furthermore, the front unit can simultaneously incorporate interlockingmeans for preventing simultaneous actuation of the keys or push buttons,something which is not possible at the rear side in the case ofcomponents which have different lengths (in the direction of theh pushbutton or key slide) in accordance with the number of switches.

Finally, the housing front unit can principally serve I for an improvedguidance of the push button and the push button can be loosely connectedwith the switch plunger so that the switched-on position becomes visibleowing to an albeit minimum increase'in the depth of, the push buttonposition, so that the push button only has to move a small distance onactuation.

LIST OF SEVERAL VIEWS OF DRAWINGS The invention will now be describedwith reference to FIGS. 1 to 11 of the accompanying drawings.

FIG. I is a side view and a section through the switch unit as anilluminated push button or key in the switched-off position.

FIG. 2 shows a switch unit in accordance with FIG. 1 in the switched-onposition with the push button depressed.

FIG. 3 shows a switch component in accordance with FIG. 2 in theswitched-on position with the push button springing back.

FIG. 4 shows a switch component in accordance with FIG. I mounted in achassis.

FIG. 5 is a plan view of two switch components, mounted alongside oneanother in a chassis, with lamp contacts.

FIG. 6 is a plan view of a switch component with a rubber abutment.

FIG. 7 is a side view and section through a switch unit with limitedentrainment of the push button and in the switched-off position.

FIG. 8 shows a switch component in accordance with FIG. 7 in theswitched-on position with the push button depressed.

FIG. 9 shows a switch component in accordance with FIG. 8 in theswitched-on position with the push button springing back.

FIG. 10 shows a switch unit with a push button in the form of a pianokey and with a mechanical indication of the switch position, in theswitched-off position.

FIG. 11 shows a switch component in accordance with FIG. 10 in theswitched-on position.

DESCRIPTION OF PREFERRED EMBODIMENTS FIGS. 1 to 5 show the basicprinciple of the novel switch component. The U-shaped housing 1 with thecover plate 2 carries the fixed contact 3 and in a conventional mannerguides the switch plunger 4, which for its part has contact bridges 5.The housing 1 is extended towards the front, that is to say beyond thefront plate of the chassis (see especially FIGS. 4 and 5) by means oftwo guide lugs la and lb, on which the push button 11 or key slides. Thepush button carries a detent 13, whose hook simultaneously serves forabutment limitation on a projection of the lug 14. The helicalcompression spring 8 brings about the return movement of the switchplunger 4 and for its part rests on the one hand against the bottom ofthe housing I and above against the cover plate 2, and on the other handthe spring rests against the front collar 9 of the switch plunger 4. Itscentering is ensured by the housing projection 10 and the cover plateshoulder 2a.

The helical compression spring 17 serves for returning the push button11 or key, against which it rests on the one hand and is centered by thepin 15. The oppo site end of the spring 17 can lie either directlyagainst the projections of the guide lugs la and lb, or, as is shown inFIGS. 1 to 5, can rest against the switch plunger collar 9. For guidingthe return spring 17 there is a pin 10 on the switch plunger. This pincorresponds to the internal diameter of the spring in accordance withFIGS. 5, 7, 8, and 9.

As ah example of possible conventional detent means in the switch unitor component the U-shaped part 6 is shown which has the detent profile 7in the push button plunger 4. In this respect the U-shaped part 6 cansimultaneously serve as an interchangeable abutment for the switchplunger 4.

FIGS. 4 and 5 show an external detent means in the form of a detentslide 22 for connecting switch compo nents which are to be subject tomutual interaction.

It is possible to dispense with the abutment locking means or'latch 6ifit is a question of push button or key components which are to besubject to mutual interaction. In this case the abutment is then formedby a rubber disc or rubber coupling device 16, which on return movementof the switch plunger 4 abuts in a damped manner on the spring centeringmeans 15 of the push button 11. In accordance with FIG. 6 a rubber disc27 can be so formed that it cooperates with the abutments 1d and 12,which are located directly on the guide lugs of the housing. Thearrangement of the key or push button return spring 17 so that it restsagainst the switch plunger 4 instead of on the housing offers theadvantage that the return impact of the push button in the case ofmutual interaction is additionally braked by the spring 17. An essentialcondition for the satisfactory function of this arrangement is that thespring 17 is selected so as to be weaker than the push button switchreturn spring 8.

In the case of FIG. 1 the switch component is located in theswitched-off position; in this position the push button 11 is held bymeans of the spring 17 and the hook 13 on the abutment l4.Simultaneously also the switch plunger 4 is heldin its rest position bythe spring 8 and the rest position is limited by the rubber disc 16,which for its part rests against the push button centering piece 15.

FIG. 2 shows the same switch component with the key or push buttondepressed, in the case of which the switch plunger 4 snaps into itsworking position. In the example the formed detent projection or profile7 is held in the operational condition by the inwardly projecting limbof the U-shaped part 6.

The push button 11 is sprung back automatically into its initialposition on release, as is shown in FIG. 3, though the switch slideremains in the operational state.

In order to make the initial and operational positions visible at thepush button head, it is necessary to provide suitable mechanicalindicating means or illuminating means. FIGS. 1 to 5 show thepossibility of accommodation of a lamp within the push button.Preferably,

a lamp holder in the form of a reflector 18 is provided, which in itstapered part accommodates the lamp 19. The lamp holder is accessiblefrom the front after removal of the transparent cap 12.

In order to ensure that the push button is only illuminated in theswitched-on position a switch of the component must be used forcontrolling the lamp. Current supply in accordance with FIG. 5a is via afixed contact 23, which simultaneously carries a resilient extension 230and makes contact with a fixed pair of contact conductors 24, leading tothe lamp 19.

In order to avoid a cumbersome external connection the switch forinterruption of illumination should also be provided in the front unitof the component housing. For this purpose in accordance with FIG. 5b atleast one of the contact supply leads 24 projecting from the push buttonis connected by a resilient contact bridge 25 with the fixed contact 23.In FIG. 5b both switching operations are shown in one and the samecomponent. In the upper half of the component the switch plunger 4 islocated in the initial position and the insulating carrier 26 connectedfixedly with it holds the contact bridge 25 in a position, whichinterrupts the contact between 23 and 24. In the lower half of thecomponent in accordance with FIG. 5b the switch.plunger 4 is in theswitched-on position. In accordance with the stroke it performs it movesthe contact bridge 25 via the carrier 26 into the advanced position, inthe case of which the contacts 24 and 23 are connected. In the case ofsuch an arrangement it is only necessary to ensure that the conductor orconductors 24 extending from the push button have sufficient room fordisplacement underneath the contact bridge and do not abut on the fixedcontacts 23.

A further possibility for indicating the switched-on position, which ismade visible by a semi-depressed push button but nevertheless maintainsthe advantages of the non-rigid connection of the push button with theswitch plunger and the improved guidance of the push button, is shown inFIGS. 7, 8, and 9. Preferably, an abutment in accordance with FIG. 6 isprovided consisting of the rubber disc 27 and the abutments 1e and Id,respectively. In the sections shown only the abutments 1e mounted on theguide lug lb are shown. The principle of the invention is closelyconcerned with the hook 28 on the push button 11, which in the case ofthe switched-on position is connected with the push button collar 9.

In FIG. 7 the switch slide 4 and the push button 11 are in theswitched-off position. Between the rubber buffer 27 and the springcentering means 15 there is a small space, which in the drawing isdenoted as A. Between the hook 28 and the switch plunger collar 9 thedistance is to be denoted as b.

On depressing the push button in accordance with FIG. 8 the switch slide4 is brought into the detent position and between the hook 28 and theswitch plunger collar 9 a gap A B" comes into being.

On releasing the push button the arrangement as shown in FIG. 9 occurs.The hook 28 now becomes connected with the switch plunger collar 9 andbetween the rubber buffer 27 and the spring centering means 15 a gap ofA B" comes into being. Therefore, the push button is in a position whichlies between the detent-held switch position and the switched-offposition of the push button. The measure just described ensures that onsnapping back of the switch slide the impact is taken up by the rubberbuffer 27 and the push button itself only moves a short distance andtherefore cannot cause any heavy impact, especially as its springloading is slight.

In FIGS. 10 and 11 the function of a switch component with a piano keyand a mechanical switch position indicator is shown. The switch slide 4can in this case as well be braked by a rubber disc 27 against fixedabutments 1d, 1e on the housing lugs la, 1b on return movement. Forcarrying or journalling the piano key it is necessary to provide a pivotpoint 30 lying above the housing lugs and which is created by anU-shaped adaptor 29, which is provided for by the shoulders 29 extending in an upward direction over the two housing lugs la, lb untilthere is an engagement with the bottom 29a. and by fitting over of theshoulders 29b. The bearing means of the piano key is still more robustin an adaptor, which forms a completely closed frame and on being pushedover the housing lugs on the front snap in behind two edges, provided onthe lugs, like the abutments Id, be so that the frame cannot be pulledoff forwards.

The piano key 31 or button has inwardly directed pins 30 on both sidesand which fit into the bearing hole 30 of the adaptor 29 or the pins arearranged in the adaptor and the longitudinal holes or slots are arrangedin the piano key or button. The lever 31a acting on the switch plunger 4is attached in a fixed manner to the piano key for example by beingmoulded on though above the key a space 310 is provided in which thestrip spring 32 can be slid as far as the foremost wall of the pianokey. The spring 32, which can also be made all of a suitable plasticsmaterial, has as a first task that of returning the key. If a window 31bis provided at a suitable position inthe piano key and if the stripspring 32 is attached to the switch plunger for example by beingprovided at this end with a fork held between the spring 8 and theswitch plunger collar 9, a coloured mark 32a, which in accordance withFIG. 10 is still outside the window 31b, can be made visible in theswitched-on position in accordance with FIG. 11 in the window 31b.

Naturally, for indication in accordance with this method it is alsopossible to use a plastics material slide, also intwo colours, incombination with a strip spring 32.

Furthermore, in the piano key or in a push button it is possible toprovide any other mechanical indicator, as for example one using arotary drum or ball and adjustable hinged means, which are operated bythe switch plunger.

What I claim is:

l. A push button switch, comprising:

a housing; fixed contacts carried on said housing;

a switch plunger positioned in said housing; said plunger having an axisextending along said housing and said plunger being axially shiftablealong said axis through said housing; bridging contacts carried on saidplunger and movable therewith through said housing and positioned to beengaged with said fixed contacts;

a plunger return spring in engagement with said plunger to bias sameaxially in a direction toward a push button;

detent means engaging said plunger for holding sam nonmovably againstthe biasing of said plunger spring;

a push button located and oriented to engage said plunger; said pushbutton being shiftable axially of said plunger to shift said plungeraxially in opposition to said plunger spring; said push button beingsupported by said housing and being separate from and movableindependently of said plunger;

a push button return spring separate from said plunger return spring andconnected with said push button and normally biasing said push buttonaxially of and away from said plunger.

2. The push button switch of claim 1, further comprising an energyabsorbent abutment carried in said housing and positioned to be engagedby said plunger as said plunger is biased axially by its said returnspring, thereby to restrain spring caused motion of said plunger.

3. The push button switch of claim 2, wherein said absorbent abutment iscarried on said push button return spring.

4. The push button switch of claim 3, wherein said absorbent abutment islocated between said plunger and said push button.

5. The push button switch of claim 4, wherein said push button returnspring presses on the one hand against said push button and on the otherhand against said plunger.

6. The push button switch of claim 1, further comprising a plungerposition indicator in said push button and connected with said plungerfor indicating when said plunger is depressed axially against its saidreturn spring.

7. The push button switch of claim 6, wherein said indicator comprisesillumination means and a switch for operating said illumination means,operation of said illumination means switch to selectively light andextinguish said illumination means being dependent upon the position ofsaid plunger, and said push button being comprised so as to permitobservation of said illumination means therein.

8. The push button switch of claim 7, further comprising a lightreflector in said push button; said illumination means comprising alight source associated with said reflector; said light source and saidreflector being positioned so that the light therefrom is reflected outof said push button; said illumination means switch comprising contactsfor said light source extending into said housing and being movable withsaid push button to selectively energize said light source at differentpositions of said push button.

9. The push button switch of claim 8 wherein said illumination meansswitch further comprises cooperating contact bridges carried on saidplunger and movable therewith to be engaged by said contacts of saidlight source.

10. The push button switch of claim 1, further comprising motionrestraining means on said push button to act in opposition to said pushbutton return spring;

means on said plunger to be engaged by said restraining means, therebyto restrain said push button from full return motion due to said pushbutton return spring.

11. The push button switch of claim 1, wherein said push button is inthe form ofa pivotable key; said housing carrying a fixedly locatedpivot to which said push button key is pivotally connected; a leverattached to said pivotable key and engaging and pressing said plungeragainst its said return spring as said key is pivoted in one direction.

12. The push button switch of claim 11, wherein said push button returnspring is comprised ofa strip spring, which engages said key to normallybias said key to pivotally return from the position at which said keylever shifts said plunger.

13. The push button switch of claim 12, wherein said strip spring isconnected to and is movable axially with said plunger, while said keywhich is pivotable by means of said strip spring is not axially movablewith said plunger;

an indicator element connected with and operable by motion axially withsaid plunger by said strip spring; said indicator element being axiallyshifted with said plunger as said strip spring shifts axially, therebyaxially shifting said indicator element with respect to said key,whereby the motion of said indicator element indicates the position ofsaid plunger.

14. The push button switch of claim 1, wherein said plunger returnspring and said push button return spring are connected to operate uponeach other and to be biased against each other and said push buttonreturn spring is weaker than said plunger return spring. =l

1. A push button switch, comprising: a housing; fixed contacts carriedon said housing; a switch plunger positioned in said housing; saidplunger having an axis extending along said housing and said plungerbeing axially shiftable along said axis through said housing; bridgingcontacts carried on said plunger and movable therewith through saidhousing and positioned to be engaged with said fixeD contacts; a plungerreturn spring in engagement with said plunger to bias same axially in adirection toward a push button; detent means engaging said plunger forholding same nonmovably against the biasing of said plunger spring; apush button located and oriented to engage said plunger; said pushbutton being shiftable axially of said plunger to shift said plungeraxially in opposition to said plunger spring; said push button beingsupported by said housing and being separate from and movableindependently of said plunger; a push button return spring separate fromsaid plunger return spring and connected with said push button andnormally biasing said push button axially of and away from said plunger.2. The push button switch of claim 1, further comprising an energyabsorbent abutment carried in said housing and positioned to be engagedby said plunger as said plunger is biased axially by its said returnspring, thereby to restrain spring caused motion of said plunger.
 3. Thepush button switch of claim 2, wherein said absorbent abutment iscarried on said push button return spring.
 4. The push button switch ofclaim 3, wherein said absorbent abutment is located between said plungerand said push button.
 5. The push button switch of claim 4, wherein saidpush button return spring presses on the one hand against said pushbutton and on the other hand against said plunger.
 6. The push buttonswitch of claim 1, further comprising a plunger position indicator insaid push button and connected with said plunger for indicating whensaid plunger is depressed axially against its said return spring.
 7. Thepush button switch of claim 6, wherein said indicator comprisesillumination means and a switch for operating said illumination means,operation of said illumination means switch to selectively light andextinguish said illumination means being dependent upon the position ofsaid plunger, and said push button being comprised so as to permitobservation of said illumination means therein.
 8. The push buttonswitch of claim 7, further comprising a light reflector in said pushbutton; said illumination means comprising a light source associatedwith said reflector; said light source and said reflector beingpositioned so that the light therefrom is reflected out of said pushbutton; said illumination means switch comprising contacts for saidlight source extending into said housing and being movable with saidpush button to selectively energize said light source at differentpositions of said push button.
 9. The push button switch of claim 8wherein said illumination means switch further comprises cooperatingcontact bridges carried on said plunger and movable therewith to beengaged by said contacts of said light source.
 10. The push buttonswitch of claim 1, further comprising motion restraining means on saidpush button to act in opposition to said push button return spring;means on said plunger to be engaged by said restraining means, therebyto restrain said push button from full return motion due to said pushbutton return spring.
 11. The push button switch of claim 1, whereinsaid push button is in the form of a pivotable key; said housingcarrying a fixedly located pivot to which said push button key ispivotally connected; a lever attached to said pivotable key and engagingand pressing said plunger against its said return spring as said key ispivoted in one direction.
 12. The push button switch of claim 11,wherein said push button return spring is comprised of a strip spring,which engages said key to normally bias said key to pivotally returnfrom the position at which said key lever shifts said plunger.
 13. Thepush button switch of claim 12, wherein said strip spring is connectedto and is movable axially with said plunger, while said key which ispivotable by means of said strip spring is not axially movable with saidplunger; an indicator element connected with and operable by motionaxially with said plunger by said strip spring; said indicator elementbeing axially shifted with said plunger as said strip spring shiftsaxially, thereby axially shifting said indicator element with respect tosaid key, whereby the motion of said indicator element indicates theposition of said plunger.
 14. The push button switch of claim 1, whereinsaid plunger return spring and said push button return spring areconnected to operate upon each other and to be biased against each otherand said push button return spring is weaker than said plunger returnspring.